Publications by authors named "Bogdan Neagu"

The topic addressed in this article is part of the current concerns of modernizing power systems by promoting and implementing the concept of smart grid(s). The concepts of smart metering, a smart home, and an electric car are developing simultaneously with the idea of a smart city by developing high-performance electrical equipment and systems, telecommunications technologies, and computing and infrastructure based on artificial intelligence algorithms. The article presents contributions regarding the modeling of consumer classification and load profiling in electrical power networks and the efficiency of clustering techniques in their profiling as well as the simulation of the load of medium-voltage/low-voltage network distribution transformers to electricity meters.

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Nowadays, the demand for soft-biometric-based devices is increasing rapidly because of the huge use of electronics items such as mobiles, laptops and electronic gadgets in daily life. Recently, the healthcare department also emerged with soft-biometric technology, i.e.

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Ballistic gel was investigated as a tissue-mimicking material in an anthropomorphic cardiac phantom for ultrasound imaging. The gel was tested for its acoustic properties and its compatibility with conventional plastics molding techniques. Speed of sound and attenuation were evaluated in the range 2-12 MHz.

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Response control in the forms of stopping and slowing responses is thought to be implemented by a frontal-subcortical network, which includes the subthalamic nucleus (STN). For manual control, stopping is linked to STN beta (13-30 Hz) and slowing responses are linked to lower frequencies (<12 Hz). Whether similar STN oscillatory activities are associated with the control of spoken responses is not clear.

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We are interested in characterizing how brain networks interact and communicate with each other during voluntary movements. We recorded electrical activities from the globus pallidus pars interna (GPi), subthalamic nucleus (STN) and the motor cortex during voluntary wrist movements. Seven patients with dystonia and six patients with Parkinson's disease underwent bilateral deep brain stimulation (DBS) electrode placement.

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Eye-hand coordination is crucial for our ability to interact with the world around us. However, much of the visually guided reaches that we perform require a spatial decoupling between gaze direction and hand orientation. These complex decoupled reaching movements are in contrast to more standard eye and hand reaching movements in which the eyes and the hand are coupled.

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The effects of subthalamic nucleus (STN) stimulation on the pedunculopontine nucleus area (PPNR) evoked activities were examined in two patients with Parkinson's disease. The patients had previously undergone bilateral STN deep brain stimulation (DBS) and subsequently received unilateral DBS electrodes in the PPNR. Evoked potentials were recorded from the local field potentials (LFP) from the PPNR with STN stimulation at different frequencies and bipolar contacts.

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Increased oscillations in the beta band are thought to be related to motor symptoms of Parkinson's disease (PD). Previous studies have shown that beta-band desynchronization in the subthalamic nucleus (STN) is reduced just before and during limb movements. While the STN is part of the basal ganglia (BG)-thalamocortical circuit controlling limb movements, it is also part of the BG-brainstem projection controlling saccadic eye movements.

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The degree to which NMDA receptors contribute to hippocampal CA(1) stratum radiatum excitatory postsynaptic potentials (EPSP) is a matter of debate. This experiment was designed to resolve the issue by documenting and positively identifying the elements of the NMDA dependent component in the extracellularly recorded stratum radiatum CA(1) field potential under low stimulation conditions and in the presence of physiologic levels of Mg(2+). We show that EPSP generation consists of activation of both AMPA and NMDA receptor channels, which mediate distinct components of the recorded field potential.

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In a hippocampal brain slice two types of stimulating electrodes [single (SE) or monopolar and parallel bipolar (PE)] were used to determine the optimal protocol for single pulse microstimulation. We show that even for a constant-current power source the amplitude of stimulating current (SC) is not constant, especially for short pulse widths (PW) (<200 micros). Recording the stimulating current and computing the amount of electric charge that is passed through the microelectrode gives the best estimate of the strength of electrical stimulation.

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In a hippocampal mouse brain slice the CA1 stratum radiatum field potential evoked by electrical stimulation of the Schaffer collaterals was used to analyze the very early responses. Parallel bipolar electrodes were utilized to lower the voltage induced by the stimulating current in the recording electrode, and to keep the induced voltage within the linear range of the headstage preamplifier and the recording amplifiers. When the stimulating and recording electrodes are in saline in the same plane and same depth, the shapes of the recorded voltage and stimulating current are similar.

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Using isolated rat aortic rings perfused with Krebs-Henseleit saline, the vascular effects of angiotensin (1-7) (Ang [1-7]) and its interactions with angiotensin II (Ang II) were investigated. Ang (1-7) induced endothelium-dependent relaxation and vasodilating effects in preparations precontracted with phenylephrine. Without preconstriction, Ang (1-7) at high doses (10(-6) 10(-5) M) produced either a significant inhibition of Ang II-induced vasoconstriction or a non-tachyphylactic vasopressor response.

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